Interesting. Is there any way how to find out all the resistances of each enemy?
Not everybody posts their builds so this whole argument is kind of mute. There are many different builds using many different skills that can beat the game on ultimate. Hell you don’t even need to try and stack - resists to be able to beat the game with many different builds.
Indeed. Creating and maintaining a build thread requires time and dedication thanks to updates/gameplay changes on top of any fine-tuning the OP has to constantly do. The reality is that people who create build threads are a minority.
A single build thread can spawn any number of possible related builds but if you check several of the threads in the classes and builds section you’ll notice that quite a few of those builds guides were inspired by something as simple as a concept (NOT BiS gear/powerful skills) from other build guides.
Finally, people who post build threads are often optimization nuts. The reality though is that your build does not need to be optimized to beat the game, and creating a functional character is more an exercise in knowing how how much damage you need to do/how much HP, resists, etc. you need for your playstyle to work.
I appreciate your outlook and understanding as well. I’m happy to hear that things are mostly getting incrementally better. It is tough sometimes for us at this point in the life of the game where there’s no way we could possibly have anywhere near the number of house of experience with the game as most hardcore players do. After my development work is done, there is just not enough time left in the day (or all too often any time) to put in the kind of hours you guys do in playing the game at the highest levels / difficulties.
I’ve actually yet to do a full play-through of hardcore, since the majority of my time is spent replaying different class / skill builds over and over again ad nauseum at lower levels to try to balance those and test changes.
So mostly we have to try to follow the forum, figure out what most people agree on (which can be difficult sometimes) and then try to asses for ourselves what makes sense and to what degree it should be changed, which sometimes means slowly bumping things up or down, or making a bigger change to try to find the extreme, then reigning it back in. It’s certainly a process. 
Also while I’m here: Primordial constellations (i define this as constellations that require more Primordial than any other color affinity, so something that requires 6 order and 4 primordial doesn’t count) are under-utilized by players, and for good reason, and I could go into it but I suspect you’re all already aware and mostly okay with it. It wouldn’t exactly be the simplest thing to change either. But general blue constellations give defensive stats that are just worse than yellow constellations, or go to lightning and aether which is fine but kind of niche, where as some red/green constellations offer offensive stats that are good for any damage type (gotta get me some %OA). I’m considering doing a write-up on what I think about constellations after some of the insight I’ve gained from working on them and trying to promote tougher choices by raising their overall quality. It’s really not a big issue, almost a non-issue, but I do feel OA/speed/%hp could be put on blue constellations a little more generously to encourage them competing with the green/red ones. They’re also so… shield related.
I’ll leave this one for Zantai as constellation balance is more in his arena.
For what my opinion is worth:
There SHOULD conceivably come a point that once one gears up properly, unless they pick a horrible poorly realized build, that they should steamroll the content, and if not steamroll it, then certainly be capable of handling everything the game throws at them with minimal deaths. As it is now, I see so many posts about a melee person who gets ass-torn by the Mad Queen, and another person of ranged just ass-tearing her in kind. We need more of a middle ground without forcing people to gear solely to handle a specific type of enemy, or ideally, to handle different enemies with just a swap of a weapon type or something.
The point I am getting at here, is that it needs to be “decided” what is easiest for most builds, and hardest for most builds, and adjust accordingly to a happy medium. Are the best builds too good? Are the worst builds too terrible? It’s starting to seem that way based off of the feedback I’m seeing so far each day on here.
There also needs to be consideration for finding the close to BiS gear. If balance is so that ‘reasonably’ geared players can roll through Ultimate at pace, the feeling of getting gear that’s ‘BiS’ is diminished.
It shouldn’t feel that you’re about to die every 5 seconds, but it should feel ‘slower’ in only reasonable gear and then have a noticeable jump in power when finding the top gear.
So I guess what I’m saying is the BiS gear should provide greater damage as a focus, where defenses should be able to be solid enough with ‘reasonable’ gear. Therefore Ultimate is not harder without BiS gear, just slower.
That’s actually already the case, especially after B31 OA changes. Raising stats/resistances/HP/etc. with yellow/green gear is ridiculously easy, the tricky part is juggling that with offense which is something purple gear specializes in. Also a few builds, unfortunately, just NEED uniques to be good at what they do (not a particularly bad thing though since these builds tend to be very specialized anyway).
I wouldn’t trust the forums when it comes to figuring out which ones do very well with self-found gear and which ones don’t. A lot of forumers still have that “legendary gear or bust” mentality and would rather die in battle wearing shiny impractical purple gear than survive using practical yellows/greens.